Field of the Invention
The present invention relates to a liquid crystal display (LCD) device and a display apparatus, and more particularly, to a sealant for bonding a lower substrate to an upper substrate.
Discussion of the Related Art
LCD devices include a lower substrate, an upper substrate, and a liquid crystal layer formed therebetween, wherein an alignment state of the liquid crystal layer is changed by an electric field applied thereto, and thus, a transmittance of light is adjusted, thereby displaying an image.
Hereinafter, a related art LCD device will be described with reference to the drawing.
FIG. 1 is a schematic cross-sectional view of a related art LCD device.
As seen in FIG. 1, the related art LCD device includes an upper substrate 10, a lower substrate 20, a liquid crystal layer 30, and a sealant 40.
Although not shown in detail, a black matrix and a color filter are formed on the upper substrate 10, and a thin film transistor (TFT) and a pixel electrode are formed on the lower substrate 20.
The liquid crystal layer 30 is formed between the upper substrate 10 and the lower substrate 20. Alignment layers 12 and 22 are formed on a surface contacting the liquid crystal layer 30, for an initial alignment of the liquid crystal layer 30. That is, an upper alignment layer 12 is formed on a bottom surface of the upper substrate 10, and a lower alignment layer 22 is formed on a top surface of the lower substrate 20.
The sealant 40 is formed on an edge area between the upper substrate 10 and the lower substrate 20. The sealant 40 bonds the upper substrate 10 to the lower substrate 20 and prevents the liquid crystal layer 30 from being leaked to the outside. Therefore, the sealant 40 includes, as a main component, an adhesive component for bonding the upper substrate 10 to the lower substrate 20.
Recently, an attempt to newly design LCD devices is being continuously made for satisfying various demands of consumers, and to this end, an attempt to decrease bezel widths of the LCD devices is made. If a bezel width of an LCD device is reduced, a display surface where an image is displayed is enlarged. In order to reduce a bezel width, an area where the sealant 40 contacts the alignment layers 12 and 22 is enlarged. This will be described below in detail.
When a bezel width of the LCD device is large, an interval or a distance between an end of the upper substrate 10 and an end of the upper alignment layer 12 may be broadened, and thus, the sealant 40 may be formed not to contact the upper alignment layer 12. Also, an interval or a distance between an end of the lower substrate 20 and an end of the lower alignment layer 22 may be broadened, and thus, the sealant 40 may be formed not to contact the lower alignment layer 22.
On the other hand, when a bezel width of the LCD device is small, the interval or a distance between the end of the upper substrate 10 and the end of the upper alignment layer 12 should be reduced, and for this reason, it is difficult to form the sealant 40 so as not to contact the upper alignment layer 12. Also, since the interval or the distance between the end of the lower substrate 20 and the end of the lower alignment layer 22 should be reduced, it is difficult to form the sealant 40 so as not to contact the lower alignment layer 22. Therefore, as illustrated, the sealant 40 contacts the alignment layers 12 and 22.
However, an adhesive force between the upper substrate 10 and the lower substrate 20 is more reduced in a case, where the sealant 40 is formed to contact the alignment layers 12 and 22 for reducing a bezel width of the LCD device, than a case where the sealant 40 is formed not to contact the alignment layers 12 and 22.